1. Technical Field
Embodiments of the present disclosure relate generally to communication systems, and more specifically to techniques for detection of signals in multiple-input multiple-output (MIMO) communication systems.
2. Related Art
Multiple-input multiple-output (MIMO) communication systems (MIMO systems) generally refer to systems in which multiple antennas are employed for communication between a transmitting device (MIMO transmitter) and a receiving device (MIMO receiver). As is well known in the relevant arts, MIMO technology provides several benefits such as increased data throughput, resistance to signal fading due to multi-path propagation effects, etc. MIMO technology is currently utilized in wireless communication according standards such as, for example, IEEE 802.11n, WiMAX, IEEE 802.11ac, LTE, LTE-A etc.
A MIMO transmitter with N antennas may be designed to transmit N symbols in a ‘symbol period’, one each from each of the N antennas. Thus, N symbols may be transmitted in each symbol period. One of several modulation techniques may be used to transmit each of the symbols. In addition, suitable encoding techniques may be employed in the MIMO transmitter to generate the symbols prior to modulation. A corresponding MIMO receiver with M antennas (M being equal to or different from N) may receive, on each of the M antennas, a superposition of the N symbols altered by the wireless channel during propagation from transmitter to receiver. Detection refers to determination (or estimation), at the MIMO receiver, of the values of each of the N transmitted symbols in each symbol period.
In MIMO systems that employ large numbers of antennas (for example, to achieve high data transmission rates), the process of detection may be associated with correspondingly high computational complexity. Another concern with detection techniques in a MIMO receiver may relate to performance (or reliability). In general, the detection needs to determine (or estimate) the transmitted symbols accurately, or at least within a desired error margin, usually specified in terms of bit-error rate (BER). In general, a lower BER corresponds to a better performance of the detection techniques, and vice-versa.
Therefore, it may be desirable that detection techniques used in MIMO systems be designed for achieving high reliability (near-optimal performance) and/or relatively low computational complexity.